目的　探讨 β 连环素 (β catenin ,β cat)和上皮钙粘附素 (E cadherin ,E cd)在大肠癌发生、发展中的作用。方法　采用免疫组织化学方法检测 2 5例正常人大肠黏膜、42例大肠腺癌、1 9例腺瘤癌变及 58例大肠癌组织的 β cat、E cd的表达情况。 结果　正常大肠黏膜 β cat、E cd呈胞膜阳性表达。大肠腺瘤、腺瘤癌变和大肠癌组织 β cat表达特征发生改变 ,胞膜表达缺失 ,呈胞质和 /或胞核异位表达 ,腺瘤癌变 β cat异位表达率 89 5 % ,显著高于大肠腺瘤 (42 9% ,P <0 0 1 )和大肠癌 (65 5 % ,P <0 0 5)的表达率 ;β cat异位表达与大肠癌的组织分化程度、淋巴结转移、Dukes分期 (大肠癌的临床分期 )等因素有关。大肠癌 β cat、E cd胞膜表达缺失率分别为 77 6 %、70 7% ,显著高于大肠腺瘤 (33 3 %、2 8 6 % )和腺瘤癌变 (42 1 %、36 8% ) (P <0 0 1 ) ,且与大肠癌淋巴结转移和Dukes分期有关。结论　β cat的异位表达可能参与了大肠癌发生、发展过程 ;β cat、E cd胞膜表达缺失可能与大肠癌的侵袭和转移有关 Objective To investigate the role of β catenin (β cat) and E cadherin (E cd) in the development and progression of colorectal cancer. Methods The expressions of β cat and E cd in 25 cases of normal human colorectal mucosa, 42 cases of colorectal adenocarcinoma, 19 cases of adenocarcinoma and 58 cases of colorectal carcinoma were detected by immunohistochemistry. Results Normal colorectal mucosa β cat, E cd were positive for membrane expression. The expression of β cat in colorectal adenoma, adenoma carcinomas and colorectal cancer tissues was changed, the expression of cytoplasm was absent, cytoplasm and / or nucleus were ectopic, and the expression rate of β cat in adenoma was 89 5% The expressions of β-catenin in colorectal adenoma (42 9%, P 0 01) and colorectal carcinoma (65 5%, P 0 05) were correlated with the histological grade, lymph node metastasis, Dukes Staging (colorectal cancer clinical stage) and other factors. The loss rates of β cat and E cd in colorectal cancer were 77.6% and 70.7%, respectively, which were significantly higher than those in colorectal adenoma (33.3%, 286%) and adenoma (42.1%, 36.8% ) (P <0.01), and it was related to lymph node metastasis and Dukes staging in colorectal cancer. Conclusion The ectopic expression of β cat may be involved in the carcinogenesis and progression of colorectal cancer. The loss of β cat and E cd expression may be related to the invasion and metastasis of colorectal cancer